Method of gumming and drying adhesive on flat surfaces



Sept. 2 1938 E. G. STAUDE 30,605

1 METHOD OF GUMMING AND DRYING ADHESIVE ON FLAT SURFACES Filed June 8, 1936 (r) mvsnvbe I ED I/Y STHUDE BYgJZ a-r Tole/ylsvs Patented Sept. 20, l

' UNITED STATES METHOD or GUMMING AND name AD- nesrvn N FLAT summons Edwin G. Staude, Minneapolis, Minn. Application June a, 1936, Serial No. 84,084

4 Claims.

This invention relates to method and means for hastening drying of adhesive applied to articles while being fed toward a delivery point, an object being to obtain-quick drying, so that it is unnecessary to reduce the speed of the machine in order that the articles'may be perfectly dry before they reach the delivery end of the machine. i

This invention also relates to mechanisms for applying adhesive to flat surfaces of paperblanks and the like, and for quickly drying the adhesive after application.

The particular application of this invention is for gumming and quickly drying the, sealing flaps ofopen side or open end envelopes, but the invention is not entirely limited to the particular type of article handled.

The usual practice is to first feed the envelope blanks in overlapped relation and to gum the entire exposed sealing flap surface during feeding and later to expose the gummed surfaces to either gas or electric heat, supplementedby a fan to quickly remove the vapor or moisture dried out of; the gum or adhesiveby the heat. This pro- 5 ceclure is quite unsatisfactory for various reasons.

It-is necessary that the adhesive be of a smooth, even-flow consistency to. obtain even app ication to the surface of the blank. This adhesive has a certain moisture content which must be absorbed by the paper or evaporated, to prevent accidental or premature stickingto the envelope, before use in the ordinary manner.

To carry out my process, I have devised a machine in which provision is made for handling envelope seals of varying widths up to two inches,

and there is'provided a chain" or pocket into which each individual blank is delivered after the adhesive has been applied, and a distance of not less than two inches is allowed for each blank.

minutes for the adhesive to dry under the present methods, and since the present high speed envelope machines are easily capable of feeding and folding five hundred envelopes per minute, it follows that the chain or '.pocket will have to include a sufficient number of pockets so as to provide a minute and a halfs operation of the machine which, if running at 500 R. P. M., would mean seven hundred fifty pockets. Since each "pocket occupies a distance of two inches, the total length of the chain or "pockets must therefore be fifteen hundred inches or one hundred twenty-five feet. I

Inasmuch as the dried blank cannot be returned .55 to its starting point in the chain or pocket,

Since it takes approximatelyone and a half there is a moist atmosphere, the drying is consid- I erably slower and it is therefore common practice to reduce the speed of the machine so as to give sufficient time for proper drying.

In the practice of my method, herein described, I instantly absorb the extra moisture, by dusting" powdered adhesive on the freshly gummed surface to absorb the moisture and dry the freshly gummed surface to prevent accidental adhesion when the sealing flap is folded over.

Features of the invention include the use of adhesive in two forms, respectively wet and dry; the use of one form of adhesive as a supplement of another form to increase the amount of adhesive and ultimate adhesive action and to hasten drying; the use of a common powder both as a base for liquid adhesive and as a drying powder, the one supplementing theother; the use of a. powder to which water is added to make a liquid adhesive and the use of the same powder as a duster for drying; the consecutive application of wet adhesive and a dusting powder which will hasten drying but will not interfere with adhesive quality when the adhesive is subsequently moistened for use after drying, and broadly the scheme of hastening drying by the application of means other than hot air, which acts while the articles are being fed or are moving.

Objects, features and advantages of the invention will be set forth in the description of the drawing forming a part of this application, and in said drawing- Figure 1 is a somewhat diagrammatic top plan view showing the relation 'of the blanks to the feeding means, and to the adhesive applying and adhesive drying means:

Figure 2 is a diagrammatic side view showing means by which my process is carried out; and

Figure 3 is a plan of the gummed side of a blank of the type shown in Figure 1.

In the drawing, 2 indicatesa conventional type of feeder having a-hopper 3 adapted for feeding the blanks 4 in overlapped relationship at the point 5 and between'the rollers 6 and l which operate at a slower speed than the feeder 2, in order to produce the overlapped relationship of the blanks. The speed at which this feeder operates determines the distance of overlap.

:operates a centrifugal force.

2 r g I Bottom carrier belts 8 and 9 are provided for supporting the outer edge of the blank, and these in turn have cooperating upper stretches of belts l and II.

A guide roller I2 is provided, and a belt l3 and I4 passing around the guide roller l2 and the roller 6, serve to guide the blank into position, and said blanks are carried forward between the belts 8 and 9, and ill and H.

Numeral l5 indicates a glue reservoir in which glue drum i6 having alrotary glue wheel scraper I! for regulating the amount of flow on the surface of the glue drum l6. Suit;

able driven rollers i8 and i9 serve to hold the envelope blanks with the exposed sealing flaps in contact with the glue drum IS. The glue drum i6 is of the required width to applyadhesive over the entire exposed sealing flap. The rollers i8 and is are offset from the center ,of the adhesive applying glue drum sufficiently so that the adhesive will not transfer from the adhesive-applying glue drum to the rollers l8 and i9 when the machine is running empty, that'is when no blanks are passing through same.

Directly after adhesive application, as just described, I apply dusting powder for which purpose I use a spinner or dusting wheel 20 having short pointed flutes. 2|; spaced a short'distance away from the gummed surface of the blanks. The spinner wheel 20 operates in a-hopper 22 and extends the same distance across the machine as theglue 'drum H6. The hopper 22 is filled with any sort of moisture absorbing material. I contemplate the use of gum or dextrine flour,.or a dry composition of the same material from which the liquid sealing flap gum is made, except that it is in powde'red form. These are features of the invention.

'Thefspinner wheel 20 revolves in this powder, in receptacle 22, and the speed is sufficient to cause theflute's 2! to throw the powder against the freshly gummed surfaces of the blanks, by 7 By this method, the needed amount of applied liquid adhesive can be considerably less because of the added dry powdered. adhesive base which supplements the previously applied adhesive to give the required total amount of adhesive necessary to give a quick and permanentseal after remoistening for use.

By this invention, the adhesive can be applied in a thinner film, and therefore contains less moisture. Therefore, less absorbent material is needed to dry the surface and moreover, the

' original wet adhesive applicatiom'withthe addition of dry powdered adhesive, results in that thickness and amount of adhesive film which is necessary to make for perfect gummed sealing, when the gum is remoistened for ultimate use.

I may provide various means to remove the surplus dust or powder, either depending upon gravity or I may agitate the blank at this point and release the surplus powder by jarring. Also, I may use one or more brushes to remove the surplus powder.

In the drawing, I have provided a receptacle 23 in which receptacle are two'revolving brushes 24 and 25. These brushes revolve in directions opposite to thatof the directions of travel of the glue drum and the spinner wheel, and serve to remove the surplus dry adhesive which is not absorbed orwillnot adhere to the freshly gummed surfaces The surplus material is collected in the bottom of the receptacle '23 and by suitable ,means (not shown) is transferred to the hopper 22.-,As-.the blanks leave the brushes 24'and'25,

ing a distancenot exceeding, thirty-six. inches.

I have shown the gumined envelope blanks delivered between the rollers 25 and 21, which support the opposite ends of the upper belt ill and the lower belt 8. It is understood that from this point "the blanks are separated by another mech .anism and the operation of creasing and folding the envelope is then completed.

Where I do the creasing and folding before gumming the sealing flap, the arrangement of advancing the blanks will, of course, be different, but it will not in any essential manner depart from my invention. I

While I have shown in the drawing a series of overlapped envelopes being .gummed, I, of course, can alter the arrangement of the blanks by having a gummer adapted to the exact outline and gumming the surface of the envelope blanks as they are being fed end to end instead of overlapping, and even do this gumming after the envelope has been folded but before the sealing flap is folded.

' I do not, therefore, confine myself to the exact manner of feeding the blanks to the gummer or the manner of delivering them after they are gummed and dried.

Instead of dusting on a dry powder, I may also spray the powder on and remove the surplus by vacuum means, or I may spray on a quick drying liquid to cover the adhesive with a film of non-sticking material which will either be On so thin as not to destroy the sticking qualities upon .re-moistening or which will evaporate enough during the time that the adhesive dries naturally.

After applying the dry powder to the surface of the adhesive, I may spray a liquid mixture on the dry powder, which liquid may include glycerine or other non-adhesive agent which will penetrate the dry powder slowly without causing adhesive qualities unless remoistened but which will slowly convert the dry powder into the same adhesive characteristics as the liquid adhesive.

All of the above schemes are contemplated in my drying process, because I believe myself the 'first to quickly dry liquid adhesive by means powdered adhesive of a character and in an amount suiiicient to quickly dry the wet adhesive during the rapid motion of the article through the machine, and without the use of. other drying means, and to obtain a needed total quantity of adhesive.-

2. A process for quickly drying adhesive applied to articles in motion in a high speed machine comprising the steps of, applying consecuplied to articles in motion in a high speed machine comprising the steps of, applying consecutively to the same region of each article, a Water soluble liquid adhesive, and a water soluble dry powdered adhesive of a character and in an amount suflicient to quickly dry the wet adhesive during the rapid motion of the article through the machine, and without the use of other drying means, and to obtain a. needed total quantity of adhesive, and applying said powdered adhesive by throwing the same against the previously applied wet adhesive. 3

4. A process for quickly drying adhesive applied to articles in motion in a high speed machine comprising the steps of, applying consecutively to the same region of each article, a water soluble liquid adhesive selected from a group consisting of gum and dextrin, and a dry powdered adhesive selected from the same group, and of a character and in an amount sufilcient to quickly dry the wet adhesive during the rapid motion of the article through the machine, and without the use of other drying means, and to obtain a needed total quantity of adhesive.

EDWIN G. STAUDE. 

